JP2723082B2 - Oxide magnetic body and magnetic sensing element using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a material having a magnetoresistance effect and a high-sensitivity magnetic sensing element using the same.

[0002]

2. Description of the Related Art Conventionally, magnetic thin films of magnetic sensors and thin-film magnetic heads utilizing the magnetoresistive effect have been formed by using metallic magnetic materials centering on permalloy. Such a magnetoresistive element utilizes a difference in resistance generated depending on the relative angle between the current direction of Permalloy and the direction of magnetization. However, the magnetoresistance change rate is as small as about 3 to 4%. For high sensitivity, a material having a large magnetoresistance change rate is desired. The rate of change in magnetoresistance ΔR / R here
The resistance value R _H of a magnetic field the minus resistance R _o of zero magnetic field from the resistance value R _H of a magnetic field as Equation 1 below
It means the value divided by.

[0003]

(Equation 1) In recent years, as a magnetoresistive material having a higher sensitivity than permalloy, for example, the 69th meeting of the Japan Society of Applied Magnetics (19)
91) Fe / Cr / F described on pages 21-26.
e, IEE Transactions on Magnetics Vol. 18, No. 2, Issue 1982-7
Pages 07 to 708 (IEEE Transaction)
on Magnetics, Vol. Mag-18, N
o. 2 (1982), 707-708), Ni / NiO / Ni, Physical Review B No. 4
Vol. 3, No. 1 (1991), pages 1297-1300 (Ph
original Review B, vol. 43, N
o. 1 (1991), 1297-1300).

More recently, La- (Ca, Sr) -Mn
In oxides having a perovskite-type crystal structure composed of -O, an extremely large magnetoresistance change ratio of 50 to 100000% has been observed (Applied.
Physics Letters 63, 14 (199
3), 1990-1992 (Applied Phy
sics Letters, vol. 63, No. 14
(1993), 1990-1992) or Applied Physics Letters 64, 22 (199).
4), pp. 3045-3047 (Applied Phys)
sics Letters, vol. 64, no. 22
(1994), 3045-3047)). For example, according to Japanese Patent Application Laid-Open No. 6-237022, L deposited on an MgO (100) substrate by an ion beam sputtering method.
In the thin film of a _1-x Ca _x MnO ₃ , a giant magnetoresistance change rate of -50% at the maximum was observed, and a magnetoresistive element was formed using the thin film of this material. Also, Applied Physics Letters 64, 22 (199
4), 3045-3047 (Appl. Phys. Le)
tt. , Vol. 64 (1994), 3045-304
According to 7), La _0.66 Ca _0.33 MnO deposited on LaAlO ₃ by pulsed laser deposition.
_In the thin film of No. ₃ , an extremely large magnetoresistance change rate of up to -127000% is observed. Where L
The reason why an oxide having a perovskite crystal structure composed of a- (Ca, Sr) -Mn-O exhibits a large magnetoresistance effect will be briefly described below. This La-
(Ca, Sr) -Mn-O-based oxide has a ferromagnetic temperature.
When the temperature is sufficiently lower than the paramagnetic transition temperature, the spins of the conduction electrons of the Mn ions are ferromagnetically aligned and exhibit metallic electrical conductivity. However, when the temperature is near or above the ferromagnetic-paramagnetic transition temperature, the spin becomes Disorder and the electrical resistance rises. The negative giant magnetoresistance effect in the La- (Ca, Sr) -Mn-O-based oxide is that the disorder of the spin order is restored by an external magnetic field near the ferromagnetic-paramagnetic transition temperature, and the conduction electrons are restored. It is thought to be caused by ferromagnetic alignment.

[0005]

With the recent demand for higher density of magnetic recording and higher sensitivity of magnetic sensors, a material which exhibits a large resistance change with a smaller magnetic field change (that is, a material having a high magnetic field sensitivity) is required. However, in the above-mentioned conventional materials, the so-called saturation magnetic field is as large as 0.1 to several T, and an extremely low temperature of −200 ° C. or less is required to obtain the large magnetoresistance change rate as described above. There were major drawbacks.

For example, the aforementioned La- (Ca, Sr) -Mn
In an oxide having a perovskite crystal structure composed of —O, the direction of the external magnetic field is c-axis direction,
Since the spins of the n ions are not only ferromagnetically coupled in the c-plane but also antiferromagnetically coupled between the c-planes, the n-ion spins around the ferromagnetic-paramagnetic transition temperature in a small external magnetic field Spin disorder cannot be fully repaired. In addition, this oxide has a ferromagnetic-paramagnetic transition temperature of about -200 ° C.
And had the disadvantage of being quite low.

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetic sensing element utilizing a magnetoresistive effect, which has a high saturation magnetic sensing capability using a material having a small saturation magnetic field and a sufficiently large magnetoresistance change even at room temperature. It is to provide an effect material. In particular, in order to overcome the above-mentioned drawbacks of the conventional materials, in order to reduce the saturation magnetic field in the magnetoresistance effect of the oxide magnetic material, a material design is performed so that spin disturbance is sufficiently restored even in a weak magnetic field, and In order to obtain a large magnetoresistance change, a material having a ferromagnetic-paramagnetic transition temperature near room temperature is selected.

[0008]

According to another aspect of the present invention, there is provided a magnetic sensing element comprising a magnetoresistive layer and a pair of electrodes provided on the magnetoresistive layer, wherein the magnetoresistive layer includes a plurality of electrodes. As an oxide magnetic material, (A ' _1-x A _x ) _{n + 1
(Mn 1-y M y)} n O z ( where, A is a lanthanoid,
At least one element of Y and Bi. A 'is at least one element among alkaline earth metals and Pb. M is Ni, C
at least one element of u. Also, 0 <x, y ≦ 0.
5, 3n ≦ z ≦ 3n + 2, n = 1, 2, 3) or (BiO) ₂ [(A _1−x A ′ _x ) _n (Mn _{1− y My} )
_{n + 1} Oz] (where A is a lanthanoid, at least one element of Y and Bi. A ′ is an alkaline earth metal and at least one element of Pb. M is Ta, Nb, Ti, Zr
At least one element of the above. Also, 0 ≦ x ≦ 0.5, 0
≦ y ≦ 1, 2n + 2 ≦ z ≦ 3n + 4, n = 3,4
5) or (Bi _1-x B _x O) ₂ [A _{n + 1} (Mn _1-y
M _y ) _n O _z ] (where A is at least one element of alkaline earth metals, B is at least one element of Pb and Tl, M is at least one element of Ni and Cu, and 0 0.5 <x <1, 0 ≦ y ≦ 0.5, 2n + 2 ≦ z ≦
3n + 2, n = 1, 2, 3, 4).

[0009]

FIG. 1 is a sectional view of a magnetic sensing element of the present invention, and FIG. 2 is a sectional view of a composite magnetic head to which the present invention is applied.
FIG. 5 shows an example of a magnetic disk drive using the composite magnetic head of FIG.

First, as a material of the substrate 1 for forming the oxide magnetic layer 2, a non-magnetic (electrically) insulating material is used. When used as a composite type magnetic head as shown in FIG. 2, a substrate in which a lower magnetic shield layer 12 is formed on a nonmagnetic and insulating base material 11 is used to prevent confusion due to a leakage magnetic field of the reproducing head.

Next, any of the following oxide materials is used for the oxide magnetic layer 2 in FIG. 1 and 13 in FIG.

A _1-x A ′ _x Mn _1-y M _y O _z (where A is at least one element of lanthanoid, Y and Bi. A ′ is at least one element of alkaline earth metal and Pb) M is at least one element of Ni and Cu, and 0 <x, y ≦ 0.5, 2.5 ≦ z ≦ 3.5) (A ′ _1−x A _x ) _{n + 1} (Mn _{1 -y} M _{y) n} O _z (where, a is a lanthanoid, Y, at least one element .A 'is an alkaline earth metal of Bi, at least one element .M of Pb is Ni, at least one of Cu 1 element, 0 <x, y ≦ 0.5, 3n ≦ z ≦ 3n + 2,
n = 1, 2, 3) (BiO) ₂ [(A _1−x A ′ _x ) _n (Mn _{1− y My} )
_{n + 1} O _z ] (where A is at least one element of lanthanoid, Y and Bi; A ′ is at least one element of alkaline earth metal and Pb; M is one of Ta, Nb, Ti and Zr) And at least one element of 0 ≦ x ≦ 0.5, 0 ≦ y ≦ 1,
2n + 2 ≦ z ≦ 3n + 4, n = 3, 4, 5) (Bi _1−x B _x O) ₂ [A _{n + 1} (Mn _{1− y My} ) _n O
_z ] (where A is at least one element of alkaline earth metals; B is at least one element of Pb and Tl; M is N
i, at least one element of Cu. Also, 0.5 <x
<1, 0 ≦ y ≦ 0.5, 2n + 2 ≦ z ≦ 3n + 2, n =
1, 2, 3, 4) Further, a pair of electrodes 3 (or 14 in FIG. 2) of FIG. 1 for reading out a magnetoresistance change occurring in the oxide magnetic layer 2 (or 13 of FIG. 2) of FIG. It is provided on the oxide magnetic layer 2 of FIG. 1 (or 13 of FIG. 2). As a material of the electrode 3 in FIG. 1 (or 14 in FIG. 2), a metal or a conductive oxide can be used. The electrode 3 in FIG. 1 (or 14 in FIG. 2) usually has a configuration including a pair of voltage application terminals and a pair of current detection terminals, and the pair of terminals includes a constant current supply terminal and a voltage detection terminal. The configuration may also be used.

In the case of the composite type magnetic head as shown in FIG. 2, an upper magnetic shield layer 15 is formed to prevent the read head from being confused due to a leakage magnetic field.
6. A recording head including an upper magnetic film 17 and a coil 18 is provided.

Here, in the pseudo-perovskite oxide as shown in FIG. 3, Mn at the B site as shown in FIG.
Since ions and Ni (or Cu) ions have different valences, they are ordered and arranged so that adjacent elements are different from each other across the O ions. Also, Mn ions are in a trivalent or tetravalent state, and the number of electrons in the d orbital is 5 or less, while Ni (or Cu) ions are in a divalent or trivalent state, Since the number of electrons in the d orbital is 5 or more, the mutual spins of Mn ions and Ni (or Cu) ions, which are arranged substantially in a straight line with the O ions interposed therebetween, are the so-called super-exchange interaction via O ions. It is considered that ferromagnetic materials are easily aligned.
Further, since the interaction between Mn ions and spins on Ni (or Cu) ions is relatively strong, this oxide material can have a ferromagnetic-paramagnetic transition temperature close to room temperature, and has a small ferromagnetic-paramagnetic transition temperature even at room temperature. The disturbance of the spin is sufficiently repaired by the magnetic field, and a large magnetoresistance change occurs. Similarly, ~
In the layered oxide shown in FIG. 1, the mutual spins of Mn ions and Ni (or Cu) ions are likely to be ferromagnetically aligned by so-called super-exchange interaction via O ions. The turbulence is sufficiently repaired, and the resistance is greatly reduced.

In addition, Bi as shown in (or)
In a layered oxide, as shown in FIG. 4, [(A _{1 -x} A ′ _x )
_{n (Mn 1-y M y} ) n + 1 O z] ( or [(A _1-x A '
_x) has a _{n (Mn 1-y M y} ) n + 1 O z]) perovskite layer which is expressed by (Bi ₂ O ₂₎ separated in layers by layer structure, (Bi ₂ O ₂ ) MnO sandwiching layers
_Since the spin coupling between the _two planes (that is, the c-plane) is weak, even a relatively small magnetic field can repair the disorder of the spin and further reduce the saturation magnetic field.

If a composite magnetic head as shown in FIG. 2 to which the magnetic sensing element of the present invention is applied is used, a high-performance magnetic disk device as shown in FIG. 5 can be manufactured. A magnetic disk 21 having a recording medium on both sides is rotated by a spindle motor 22, and an actuator 23 guides a head slider 24 onto a desired track of the recording medium. The reproducing head and the recording head of the composite magnetic head formed on the head slider 24 move relatively close to the recording medium by this rotation, and write or read signals sequentially. The recording signal is recorded on the recording medium by the recording head through the signal processing system 25, and the output of the reproducing head is read as the recording signal through the signal processing system 25.

[0017]

【Example】

 (Embodiment 1) An embodiment of the present invention will be described with reference to FIG.

FIG. 6 is a sectional view of a composite magnetic head in which the magnetic detecting element of the present invention is applied to a reproducing portion. The composite magnetic head includes a reproducing head to which the magnetic detecting element of the present invention is applied, an inductive recording head, and a magnetic shield for preventing the reproducing head from being disrupted by a leakage magnetic field. The reproducing head is Al ₂ O ₃ −
A base comprising a TiC composite ceramic base material 30 and a lower magnetic shield layer 31 formed on the base material 30 is used, and an oxide magnetic layer 32 is formed on the base as La _0.7 Sr _0.3 Mn _0.5
Ni _0.5 O ₃ was formed by the laser ablation method under the conditions shown in Table 1 below. X-ray diffraction (XRD) revealed that the oxide magnetic layer 32 thus formed was polycrystalline. Also, by controlling the growth conditions appropriately, the ferromagnetic-paramagnetic transition can be caused in the oxide magnetic layer 32 at around room temperature. Thereafter, the oxide magnetic layer 32
A Pt layer having a thickness of 200 nm was formed thereon as an electrode 33, and an upper magnetic shield layer 34 was further formed thereon to obtain a reproducing head.

[0019]

[Table 1] Finally, a recording head including the lower magnetic film 35, the upper magnetic film 36, and the coil 37 was formed to form a composite head.

The composite type head thus produced exhibited a magnetoresistance ratio of -30% at room temperature by an external magnetic field of 1000 Oe. Further, the magnetoresistance change rate was the same whether the applied external magnetic field was parallel or perpendicular to the film surface, and showed an isotropic magnetoresistance effect.

After the electrode 33 has been formed,
Annealing at 00 to 600 ° C. further increased the rate of change in magnetoresistance, confirming improvement in magnetic field detection sensitivity.

In this embodiment, the case where La _0.7 Sr _0.3 Mn _0.5 Ni _0.5 O ₃ is used as the oxide magnetic layer 32 has been described, but instead of La, Y, Pr, Nd, E
u, Dy, Yb or Bi, and C for Sr
a, Ba, or Pb, and further, Cu can be used instead of Ni.

(Embodiment 2) An embodiment of the present invention will be described with reference to FIG.

A Si wafer 41 whose surface is thermally oxidized,
a 50 nm thick Ti layer 42 formed on the i-wafer 41 by DC sputtering, a 200 nm thick Pt layer 43 formed on the Ti layer 42 by DC sputtering,
Thickness of 200 grown on layer 43 by RF sputtering
An oxide magnetic layer 45 is formed on a substrate composed of a polycrystalline SrTiO ₃ layer having a thickness of (Y _0.7 Sr _0.3 ) ₃ (M
n _0.5 Cu _0.5 ) ₂ O ₇ was formed by ion beam sputtering under the conditions shown in Table 2 below. XRD confirmed that the oxide magnetic layer 45 thus formed was polycrystalline.

[0025]

[Table 2] Further, on the oxide magnetic layer 45, an electrode 46 having a thickness of 200
nm of RuO ₂ was formed by DC sputtering. The magnetic sensing element thus produced exhibited a magnetoresistance ratio of −20% at room temperature with an external magnetic field of 1000 Oe.

Further, by forming an alumina layer as a protective layer 47 on the electrode 46 by RF magnetron sputtering, it is possible to prevent the oxide magnetic layer 45 from deteriorating due to moisture in the air and the like, and to improve the reliability of the element. Can be improved.

As a substrate, Al ₂ O ₃ , MgO, S
A polycrystal or single crystal of rTiO ₃ or LaAlO ₃ , and Pt, Al, Ti, Ta, Au, W, S
i, Cu, Ag and their alloys, or TiN, Ir
O ₂ can also be used. Further, as the electrode 46,
When Pt, Au, or TiN, IrO ₂ , or RuO ₂ is used, the electrode
Annealing at 600 ° C. further increased the magnetoresistance ratio.

In this embodiment, the case where (Y _0.7 Sr _0.3 ) ₃ (Mn _0.5 Cu _0.5 ) ₂ O ₇ is used as the oxide magnetic layer 45 has been described, but La, Pr,
Nd, Eu, Dy, Yb or Bi, Ca, Ba or Pb instead of Sr, and N instead of Cu
i can be used.

(Embodiment 3) An embodiment of the present invention will be described with reference to FIG.

The substrate 51 is made of single-crystal LaAlO ₃ (10
(Bi _0.35 Pb _0.65 O) ₂ (Sr ₂ Ca) as an oxide magnetic layer 52 on a substrate 51 using a mirror-polished substrate
Mn ₂ O ₆ ) was formed by RF magnetron sputtering under the conditions shown in Table 3 below. As a result of XRD, it was confirmed that the oxide magnetic layer 52 thus formed was strongly oriented in the <100> direction.

[0031]

[Table 3] Further, on the oxide magnetic layer 52, an electrode 53 having a thickness of 300
nm of Au was formed by a direct current sputtering method, and an alumina layer was formed thereon as a protective layer 54 by an RF magnetron sputtering method. The magnetic sensing element thus prepared exhibited a magnetoresistance change rate of -25% at room temperature by an external magnetic field of 1,000 Oe (the magnetic field was parallel to the film surface). Furthermore, the magnetoresistance change rate differs between when the applied external magnetic field is parallel to the film surface and when it is perpendicular, and when the external magnetic field is parallel to the film surface, the magnetoresistance change rate increases slightly. The effect was shown.

As the substrate 51, Al ₂ O ₃ , Mg
O, SrTiO ₃ , LaAlO ₃ polycrystal or single crystal,
Pt, Al, Ti, Ta, W, S
i, Cu, Ag and their alloys, or TiN, Ir
O ₂ and RuO ₂ can also be used. Further, the electrode 5
As Pt, Au, or TiN, IrO ₂ , R
When uO ₂ was used, annealing at 400 to 600 ° C. in oxygen after forming the electrode 53 further increased the magnetoresistance ratio.

In this embodiment, the case where (Bi _0.35 Pb _0.65 O) ₂ (Sr ₂ CaMn ₂ O ₆ ) is used as the oxide magnetic layer 52 has been described, but Tl is used instead of Pb.
Ba can be used instead of Sr and Ca. Further, a part of Mn may be replaced with Ni or Cu.

(Embodiment 4) An embodiment of the present invention will be described with reference to FIG.

As the base 61, a single-crystal MgO (100) mirror-polished substrate was used.
(BiO) ₂ [Bi ₂ (Mn _0.6 Ta _0.4 ) ₃
O ₁₀ ] was formed by the organometallic decomposition method under the conditions shown in Table 4 below. The oxide magnetic layer 62 formed in this manner has an XR
As a result of D, it was confirmed that the film was strongly oriented in the <100> direction.

[0036]

[Table 4] Further, on the oxide magnetic layer 62, an electrode 63 having a thickness of 200
nm of Pt was formed by a DC sputtering method, and a zirconia layer was further formed thereon as a protective layer 64 by an RF magnetron sputtering method. The magnetic sensing element thus prepared exhibited a magnetoresistance change rate of -25% at room temperature by an external magnetic field of 1,000 Oe (the magnetic field was parallel to the film surface). Furthermore, the magnetoresistance change rate differs between when the applied external magnetic field is parallel to the film surface and when it is perpendicular, and when the external magnetic field is parallel to the film surface, the magnetoresistance change rate increases slightly. The effect was shown.

As the substrate 61, Al ₂ O ₃ , Mg
O, SrTiO ₃ , LaAlO ₃ polycrystal or single crystal,
Further, as the electrode 63, Al, Ti, Ta, W, Si, C
u, Ag, Au and their alloys, or TiN, Ir
O ₂ and RuO ₂ can also be used. Further, the electrode 6
As Pt, Au, or TiN, IrO ₂ , R
When using uO ₂ , annealing at 400 to 600 ° C. in oxygen after forming the electrode 63 further increased the magnetoresistance ratio.

In this embodiment, the case where (BiO) ₂ [Bi ₂ (Mn _0.6 Ta _0.4 ) ₃ O ₁₀ ] is used as the oxide magnetic layer 62 has been described, but instead of Bi, Y and L are used.
a, Pr, Nd, Eu, Dy, Yb or Ca, Sr,
Ba and Pb can be used, and Nb, Zr and Ti can be used instead of Ta.

[0039]

According to the present invention, it is possible to easily realize a magnetic sensing element having high sensitivity magnetic sensing ability using a material having a small saturation magnetic field and having a sufficiently large magnetoresistance change even at room temperature.

[Brief description of the drawings]

FIG. 1 is a sectional view of a magnetic sensing element according to the present invention.

FIG. 2 is a sectional view of a composite magnetic head to which the present invention is applied.

FIG. 3 A _1-x A ′ _x Mn _{1- y My} O _z (where A is at least one element of lanthanoid, Y and Bi; A ′
Is at least one element among alkaline earth metals and Pb.
M is at least one element of Ni and Cu. Also, 0 <
x, y ≦ 0.5, 2.5 ≦ z ≦ 3.5).

FIG. 4 shows (BiO) ₂ [(A _1-x A ′ _x ) _n (Mn _1-y
M _y ) _{n + 1} O _z ] (where A is a lanthanoid, Y, Bi
At least one element of the above. A 'is an alkaline earth metal,
At least one element of Pb. M is Ta, Nb, T
At least one element of i and Zr. Also, 0 ≦ x ≦
0.5, 0 ≦ y ≦ 1, 2n + 2 ≦ z ≦ 3n + 4, n =
3, 4, 5) and (Bi _1-x B _x O) ₂ [A _{n + 1} (M
_{n 1-y M y) n} O z] ( where, A is at least one element selected from the group consisting of at least one element .M is Ni, Cu of the at least one element .B is Pb, Tl of the alkaline earth metal 0.5 <x <1, 0 ≦ y ≦ 0.5, 2n + 2
≦ z ≦ 3n + 2, n = 1, 2, 3, 4).

FIG. 5 is a conceptual diagram of a magnetic disk drive using the magnetic detection element of the present invention.

FIG. 6 is a sectional view of a composite magnetic head to which the magnetic detection element according to the first embodiment of the present invention is applied.

FIG. 7 is a sectional view of a magnetic sensor according to a second embodiment of the present invention.

FIG. 8 is a sectional view of a magnetic sensing element according to a third embodiment of the present invention.

FIG. 9 is a sectional view of a magnetic detection element according to a fourth embodiment of the present invention.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 base 2 oxide magnetic layer (magnetoresistive layer) 3 electrode 11 base material 12 lower magnetic shield layer 13 oxide magnetic layer 14 electrode 15 upper magnetic shield layer 16 lower magnetic film 17 upper magnetic film 18 coil 21 magnetic disk 22 spindle Motor 23 Actuator 24 Head slider 25 Signal processing system 30 Base material 31 Lower magnetic shield layer 32 Oxide magnetic layer 33 Electrode 34 Upper magnetic shield layer 35 Lower magnetic film 36 Upper magnetic film 37 Coil 41 Si wafer 42 Ti layer 43 Pt layer 44 SrTiO ₃ layer 45 oxide magnetic layer 46 electrode 47 protective layer 51 substrate 52 oxide magnetic layer 53 electrode 54 protective layer 61 substrate 62 oxide magnetic layer 63 electrode 64 protective layer

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location H01L 43/10 G01R 33/06 R

Claims (4)

(57) [Claims] 1. (A ' _1-x A _x ) _{n + 1} (Mn _{1- y My} )
_n O _z (where A is at least one element of lanthanoid, Y and Bi; A ′ is at least one element of alkaline earth metal and Pb; M is at least one element of Ni and Cu; 0 <x, y ≦ 0.5, 3n ≦ z ≦ 3n
+2, n = 1, 2, 3). 2. (BiO) ₂ [(A _{1 -x} A ′ _x ) _n (M
_{n 1-y M y) n} + 1 Oz] ( where, A is a lanthanoid,
At least one element of Y and Bi. A 'is at least one element among alkaline earth metals and Pb. M is Ta, N
b, at least one element of Ti and Zr. Also, 0 ≦
x ≦ 0.5, 0 ≦ y ≦ 1, 2n + 2 ≦ z ≦ 3n + 4, n
= 3, 4, 5). (Bi _1-x B _x O) ₂ [A _{n + 1} (Mn
_1-y M _y ) _n O _z ] (where A is at least one element of alkaline earth metals; B is at least one element of Pb and Tl; M is at least one element of Ni and Cu). Also, 0.5 <x <1, 0 ≦ y ≦ 0.5, 2n + 2
≦ z ≦ 3n + 2, n = 1, 2, 3, 4). 4. A magnetic sensing element comprising a magnetoresistive layer and a pair of electrodes provided on the magnetoresistive layer, wherein the magnetoresistive layer is used as the magnetoresistive layer. A magnetic sensing element using the oxide magnetic material according to any one of the preceding claims.